U.S. Secretary of Defense Ash Carter (front) and Chairman of the Joint Chiefs of Staff General Joseph F. Dunford arrive at a joint news conference at the Pentagon in Washington, U.S. July 25, 2016. REUTERS/Yuri Gripas

U.S. Secretary of Defense Ash Carter (front) and Chairman of the Joint Chiefs of Staff General Joseph F. Dunford arrive at a joint news conference at the Pentagon in Washington, U.S. July 25, 2016. REUTERS/Yuri Gripas

U.S. Secretary of Defense Ash Carter (front) and Chairman of the Joint Chiefs of Staff General Joseph F. Dunford arrive at a joint news conference at the Pentagon in Washington, U.S. July 25, 2016. REUTERS/Yuri Gripas

August 29, 2016 5:45 PM (UTC+8)